Chalcedony is a variety of quartz and includes all agates, onyx, cornelian and chrysoprase. It is built up of thin layers of tiny quartz fibres. This layered structure provides the colour banding in quartz and onyx.
This ring forms part of a collection of 154 gems bequeathed to the V&A by the Reverend Chauncy Hare Townshend, a cleric and poet. Sir A. H. Church gave additional specimens in 1913. He also compiled the first catalogue Precious Stones: A Guide to the Townshend Collection. The first edition appeared in 1883. The stones are mounted as rings, although they may not have been intended to be worn.